The playoffs are again commonplace for the 49ers. Sunday’s showdown at Carolina will mark the seventh postseason game in Jim Harbaugh’s three years as head coach.

Familiarity, though, hasn’t bred complacency. Instead, a hunger marks the 49ers’ play, a hunger produced by last year’s heartbreak. The pain of falling 5 yards shy of a Super Bowl feast drives this machine.

Or, as linebacker Ahmad Brooks put it: “Last year, we got a taste of what the Super Bowl was like. We had an entree that we didn’t get to eat. This time, we want to finish the plate.”

The 49ers should avenge their regular-season loss to Carolina on Sunday. This time, they’ll have wide receiver Michael Crabtree, and linebacker Aldon Smith figures to play more than 12 snaps. And tight end Vernon Davis and safety Eric Reid presumably won’t be knocked out of the game with concussions.

But San Francisco’s biggest advantage is the motivation of unfinished business. That wasn’t in play when Carolina won 10-9 at Candlestick Park on Nov. 10. The 49ers have been a team on a mission for weeks. And it seems the closer they get to failure, the distress of that gut-wrenching feeling Tasers them into another gear.

That is evident in Colin Kaepernick’s execution when defeat becomes tangible. In the defense’s refusal to break after bending like a spoon in the Matrix. In the timely holes opened by the offensive line to revive a struggling running game.

Coming so close to winning it all has revived the Super Bowl-or-bust reality of yesteryear.

It’s hard to see how this mentality doesn’t work in the 49ers’ favor. It has fueled them to three straight nail-biting victories. More than that, you have to wonder if Carolina is ready to match such an intensity.

Just 21 of the 53 players on the Panthers’ roster have felt the density of postseason sweat, and it’s a different beast wrestling with one who has everything to lose.

Carolina — at home, boasting a stout defense and an increasingly clutch quarterback — can definitely pull it off. But it’s becoming evident the 49ers aren’t going to give it away, the Panthers are going to have to take it. There is a difference, and it’s not small.

An upstart team, Carolina has the luxury of patience should they go one-and-done. They can chalk it up as a natural part of the development. San Francisco doesn’t enjoy such privilege.

“This is it,” Davis said. “If we lose this game, we go home. It’s simple. It’s plain. It’s right there, and guys know it. The guys that we have on our team, they’re so … they’re just desperate. They’re all in it. Especially with what happened to us last year. We got to the Super Bowl and didn’t pull it off. Now we know that here is another chance to do it all over again. We must take advantage. We must come through.”

The 49ers have won too many postseason games to fall back on development, made it too far for a second-round playoff loss to be acceptable. They’re pursuing a ring like Gollum.

They’re trying to become the first team since the 1993 Buffalo Bills to return to the Super Bowl after losing the previous year. Only the 1971 Dallas Cowboys and undefeated ’72 Miami Dolphins have won a Super Bowl after losing it the previous season. Yet, the 49ers talk about it like it’s rightfully theirs. Like fate owes them 5 yards and they plan to collect.

Certainly, the 49ers are in good position. Save for Carlos Rogers’ hamstring, they are healthy in all the right places. Key figures who have struggled at times this season seem to be hitting their form at the right time. On top of that, San Francisco has on its side experience and the consuming #QuestForSix.

William Shakespeare said “tempt not a desperate man.” The Panthers are about to find out why not. And if they’re not ready, this could get ugly.

“It’s a do-or-die situation in the postseason,” 49ers offensive coordinator Greg Roman said. “So, if you haven’t noticed, we’ll do anything to win.”

Marcus Thompson is a former sports columnist for the Bay News Group and author of "Golden: The Miraculous Rise of Steph Curry." After 10 years as an NBA beat writer, he is a leading voice on the Golden State Warriors. An Oakland native, he gives us a relevant voice in the East Bay. He's been with the organization since 1999.